Fence knob



Jan. 13, 1948. A. B. BUSSMANN FENCE KNOB Filed Jan. 7, 1944 INVENTOR. 46 m B. u 4 BY B HTTGRNEY Patented Jan. 13, 1948 UNITED STATES PATENT OFFICE FENCE KNOB Aloysius B. Bussmann, St. Louis, Mo.

Application January 7, 1944, Serial No. 517,440

This invention relates to improvements in fence knobs. More particularly this invention relates to improvements in fence knobs and improvements in supporting brackets for such knobs.

It is an object of the present invention to provide an improved fence knob and an improved supporting bracket for that knob.

Generally speaking, fence knobs are devices made of a ceramic material, such as porcelain, that has considerable dielectric strength as well as appreciable physical strength. These knobs physically connect but electrically separate an electrically charged strand of barbed wire and a fence post. That fence post, together with a number of other fence posts, usually defines the limits of a grazing or pasture area in which cattle, sheep, goats or other animals can be permitted to graze. These knobs must possess to a high degree the ability to insulate conductors of electricity from each other, because the voltage impressed on the barbed wire is quite high, and because the fence post may be a good electrical ground. Where the post is made of metal it will be a good electrical ground at all times; and where the post is made of wood it will become a good electrical ground when it gets wet, as it does during a rainfall. These knobs must not only be good electrical insulators, they must have an appreciable physical strength because they constitute the sole means of support of the strand of wire, and they are often subject to rough handling.

In addition, these knobs must be made to have a sizeable overall length so they can space the electrically charged wire from the fence post a distance great enough to prevent leakage of current from the wire to the post across the surface of the knob. As a result the knobs are usually longer than they are wide and may be said to be elongated bodies of insulating material.

These knobs are usually secured to the fence post by a large nail or bolt that extends through the slightly larger bore of the knob which extends through the full length of the knob. These large nails or bolts are highly objectionable for many reasons. Where they extend through the entire length of the knob, their projecting ends are subject to rust and corrosion. This rust and corrosion is only slightly soluble in water, butall' too quickly runs down the face of the knob to provide a shorting path for the electricity between the electrically charged wire and the nail or bolt. In many instances this rust and corrosion, coupled with the dust and dirt deposited on 3 Claims. (01. 174158 the knob, has in a few weeks time utterly destroyed the ability of the knob to insulate the Wire from the post. The large nails or bolts are further objectionable because they require the knobs to have a rather large diameter to prevent leakage of electricity from the wire to the nail or bolt. The large diameter of the knob is not only needed to provide the desired amount of porcelain between the wire and the nail or bolt, but it is also needed to increase the length of the air gap between the wire and the head of the nail or bolt. Since the nail or bolt is secured directly to the fence post, and since that post can be a good electrical ground, it is essential that a thick sleeve of insulating material be provided to maintain adequate spacing at all times between the electrically charged barbed wire and the nail or bolt. Since a sleeve of'this thickness can only be provided by increasing the diameter of the knob, it is clear that the use of large nails or bolts results in the provision of an unnecessarily large knob.

The large nails andbolts are objectionable for still another reason. These nails or bolts con stitute the sole means of support of the knobs and the electrically charged barbed wire secured to those knobs and therefore the nails or bolts must be quite sizable to have the necessary strength. Because they are sizable, the nails or bolts may tend to split wooden fence posts into which they are forced. The splitting of the fence posts is encountered most often where the knobs are used on posts that enclose temporary grazing areas. Such posts are often made of wood and are purposely made lightweight so they can be uprooted easily; but unfortunately their light weight also causes them to split when the large nails or bolts are forced into them. Of course, any such splitting is objectionablebecause it not only injures the post but it results in an insecure con-- and bolts heretofore employed in supporting fence knobs.

Instead of extending longitudinally through the geometric axis of the knob as the nails or bolts do, the supporting bracket provided by the invention preferably extends into the knob for a short distance only. As a result, it is pos- 3 sible to space the supporting bracket a considerable distance away from the electrically charged barbed wire. Consequently the diameter of the knob can be made quite small without any diminution of the insulating ability of the knob, since the bracket is spaced longitudinally from the wire and will not require a thick sleeve of porcelain. In addition, the bracket is preferably made of malleable metal so it can possess considerable resilience. Such resilience is desirable because it provides give between the knob and the fence post. It is therefore an object of the present invention to provide an improved supporting bracket for fence knobs that is made of malleable metal.

The bolts and nails customarily used to support fence knobs necessitate the provision and use of metal posts or sizable wooden fence posts; because small wooden fence posts split too easily when those'nails and bolts are used. This is objectionable because large wooden fence posts are not only more expensive but they are much more difficult to set up than are small posts. By using the supporting bracket provided by the present invention, it is possible to use small wooden fence posts and thereby decrease the cost of the fence and make it easy to set it up. Small wooden fence posts can be used with the present invention because the supporting bracket provided by the invention can use a plurality of small, rather than just one, large, post engaging means. It is therefore an object of the present invention to provide a supporting bracket for fence knobs that has a plurality of small post engaging means.

Other objects and advantages of the invention will become apparent from an examination of the drawing and accompanying description.

In the drawing and accompanying description two preferred forms of the invention are shown and described, but it is to be understood that the drawing and accompanying description do not limit the invention and the invention will be defined by the appended claims.

In the drawing, Fig. 1 is a partial cross sectional side elevational view of the fence knob incorporating the principles of the present invention,

Fig. 2 is an end elevational view of one end of the fence knob of Fig. 1,

Fig. 3 is a cross sectional view of the supporting bracket for the knob of Fig. 1, and

Fig. 4 is a plan view of the supporting bracket shown in Fig. 3.

Referring to the drawing in detail, a body of insulating material is denoted by the numeral 10. This body is longer than it is wide, and may therefore be said to be an elongated body of insulating material. The exterior of the elongated body H] has at least one, and may if desired have a plurality of, circumferential grooves l2 and a circumferential wire receiving recess l4 thereon. The groove 12 is provided to increase the surface distance frOm the recess [4 to the post, without necessitating an increase in the overall length of the body and the recess I4 is provided to facilitate the securing of the wire to the knob.

It will be noted that in the preferred form of construction shown in the drawing, the knob ll] does not have a skirt. As a result, there is no problem of mounting the knob in a particular position to avoid the collection of moisture on the inner surface of that skirt. This adds materially to the usefulness of the knobs since they may be set in a vertical or a horizontal position.

An electrically charged barbed wire can be held 4 in recess I4 by a number of different means, but will preferably be held by a wire or a clamp; either of which is well known to those skilled in the art. The clamp that is used, will preferably be of such a construction that the wire can be clamped or released quite readily. This is quite desirable to facilitate the ready uprooting and moving of the fence posts.

As the drawing shows, the recess [4 is spaced away from the base of the knob an appreciable distance. Such spacing is necessary because the barbed wire may have a charge of seventeen hundred volts impressed on it, and the knob must prevent the leaking of that charge across to the fence post.

Formed in one end of the elongated body 10 is a recess I6, I! that does not extend throughout the entire length of the knob. The recess I6, I! actually consists of a primary recess l6 and a secondaryrecess IT. The recess I1 is provided primarily'to reduce the amount of material required to make the knob, and it could be dispensed with altogether if desired. However, the recess I! is useful in decreasing the weight and the cost of the knob.

The recess IS, on the other hand, serves a more utilitarian purpose because it receives the cup like member 20 on bracket 22. From this it is apparent recess I6 is the utilitarian part of the recess 16, I! and might be said to constitute the effective depth thereof. Since the recess l! is not a part of the means securing the knob to the support, it can be of any suitable conformation and design, but it should not be so large that it unduly weakens the knob H).

In making the knob, it is desirable that the effective depth of the recess [6, ll be less thanone half of the length of the elongated knob 10, and that the interior surface of the recess be provided with a helical thread 18. Such a construction is highly desirable because a shallow recess can be used with a small bracket; and a small bracket is cheaper to make and will be more resilient than a larger bracket. The resilience is particularly desirable because it tends to soften or absorb the stresses that are transmitted to the knob, and thereby tends to diminish the stresses transmitted to the fence post itself.

Stresses are frequently transmitted to the knobs When the fence is used to define a grazing area. For instance, the animals placed within the barbed wire enclosure may try to break out, or may kick the wire, or otherwise impress stresses thereon. It has been the experience of those skilled in the art that once an animal has touched the electrically charged wire, it will not again do so; but the animal may place considerable stress on that wire in its initial touching. Such stress must be absorbed or it will immediately be communicated to the fence post. In the same way, stresses impressed on the post must be absorbed or they will be transmitted to the knob. In some cases, these stresses might injure the knob, might dislodge the post, or might loosen the supporting means for the bracket. The present invention achieves the necessary absorption of stress by providing a fence knob and supporting bracket therefor that permit the knob to move slightly relative to the post and thereby absorb at least a portion of the stress.

Not only are the knobs subject to stresses caused by animals, they are also subject to stresses caused by the farmers themselves. When the cattle, sheep, goats and other animals have eaten all of the grass or hay enclosed by the fence, the fence posts are uprooted andmoved to another site. This moving entails considerableapplication oi. stresses to the knobs merely by the recurrent tightening of the barbed wire. ln addition there maybe stresses due to the bumping o jostling of the knobs as the posts are uprooted and carried around. Because of the presence of these stresses, it is additionally necessary that the knobs and the supporting brackets therefore be especially able to absorb considerable punishment without break ing or coming loose from the fence post.

Adapted to engage the recess lfiof knob IE1 is the cup-like projection on bracket 22. This projection preferably is hollow to give it additional resilience and also to reduce the amount of 'rne'tal required to make it. In Figs. 3 and 4 the bracket is shown to have the form of a flanged cupthat has a flange of varying width. Formed as a portion of the flange are two projecting ears 23 that extend outwardly beyond the periphery of the knob when the bracket and knob are as sembled. Ihe rest of the flange preferably is narrower and will be overlain by the knob when the knob and bracket are assembled. On the exterior of this projection is a helical thread 24 that is releasably eng'ageable with the thread. l8 on the interior of recess it. In actual practice, the bracket 22 will preferably be made as a stamping and will have the thread 24 formed thereon by rolling. Two advantages from making the bracket 22 by stamping or drawing metal are the low cost and the desirable form of the bracket. Aswill be noted from the drawing, there is a rounded section 2! connecting the projection 20 with the base of the bracket 22. This rounded section is of such a shape that its surface is adapted to prevent the end of the knob it) from engaging the base of the bracket 22 and to thereby maintain an air gap therebetween.

The metal, from which the bracket is made, is preferably quite thin. Such a thin metal bracket would possess many desirable features including resilience, flexibility, lightness, ease of manufacture, and inexpensive cost. In the preferred form of invention shown in the drawing,

the wall of the projection has a thickness less than the pitch of the thread formed on the exterior surface of that projection.

Spaced from the recess Zll and positionedin the projecting ear portions 23 of the flange of the bracket are a plurality of openings 26 that are adapted to receive nails, screws, or other post engaging means. In the drawing, a pair of nails 28 are shown but any suitable post engaging means may be used. For example, a wire could be passed through the openings 28 of the bracket and bent around-the projection 20, and its free ends could be twisted around a fence post. This wire would be an excellent post engaging means for a bracket that was to be secured to a metal or concrete post.

As a matter of fact, a portion of the flange itself could be made quite sharp and could be bent to act as a post engaging means. With such a construction, only one other post engaging means would be needed. From this it can be seen that various kinds and arrangements of post engaging means can be used. Some of them may be separable from, and others may be integral with, the bracket; but whether the post engaging means are integral with or separable from the bracket, they can be said to be carried by that bracket.

The openings 26, in the preferred form of invention illustrated, are positioned so a line connecting-them passes through the geometric center of the projection 20. Furthermore, the openings 26 are preferably positioned so a line connecting them can be set parallel to the barbed wire sup ported by said knob. Such an arrangement ene-v ables the bracket to resist the forces, applied to the knob, that would tend to force the bracket securing means out of the fence post.

The bracket is well adapted to resist its dislodgment from the fence post, because it has relatively large area that will contact the post. Furthermore, the greatier portion of that con: tacting area is spaced from the axis of the knob and 'is thus better able to resist dislodging forces applied to theknob than a contact surface at the axis of the knob. Not only will the bracket have a greater and more even distribution of force, but it will have those forces spacedv away from the axis of the knob. From this it is apparent that a bracket is a more desirable support for a fence knob than is the nail or bolt customarily employed.

The provision of the plurality of bracket securing means 28 is quite desirable because the nails will most probably penetrate the Wood of the post in such a manner that they will not be exactly parallel to each other. The nails will therefore be better able to resist the removal of bracket 22 than a single nail or bolt would be, because a single force cannot be applied to the bracket that would be parallel to both nails; whereas in the case of a single nail or bolt, it would be quite easy to apply a force parallel to the single securing means. Depending on the angularity of the nails 28, those nails will co.- operate with the bracket to hold the knob as tight or tighter than a single nail or bolt of considerably larger size could hold it.

Not only does the plurality of small nails 28 cooperate with the bracket to hold the knob tighter than a single large nail or bolt would do, they are much easier to drive into the post. These posts are usually small and they are hard to hold when a large nail or bolt is being driven into them. Furthermore the large nail or bolt would tend to split the post.

Ihe exceptional holding power of a plurality of nails 28 is attested to by the fact that they hold the knob secure although the nails can be made so small that the total weight of bracket 22 and nails 28 is equal to or less than the weight of the large nails or bolts now being used. As a result, the invention provides a method of holding the bracket more securely than present methods, and it does so without using any more metal.

The use of a plurality of nails 28 in conjunction with a bracket is additionally advantageous overthe use of a single bolt or nail, because it obviates the provision and use of the leather washers that must be provided and used with single nails and bolts that extend through the knob. These washers are needed to space the head of the nail or bolt from the knob so the head of the nail or bolt may be struck with a hammer without breaking the knob. Such a washer is completely unnecessary where the bracket provided by the invention is used, and the invention saves the cost of this washer.

It is additionally desirable to avoid the use of the leather washers because they do not stand up under exposure to the elements. For example, under constant exposure to sun and wind, the washers dry up and tend to shrink. This shrinkage leaves the knob loose or the nail or bolt. Even more undesirable is the leaching out of some substance from the leather and the depositing of that substance on the surface of the knob. This substance has been found to foster the creation of a shorting path across the surface of the knob and to quickly reduce the insulating ability of the knob.

The fact that the bracket is made of a malleable metal makes it possible to bend the bracket to make it conform to the surface to which it is to be secured. Proper bending of the ears 23 of the flange will enable both of them to contact the surface of the post to which the bracket is secured, even though the surface of the post is irregular. Furthermore, the fact that projection 20 is hollow makes it possible to use the bracket on a surface that has a small projection thereon instead of being perfectly plane.

By use of the present invention it is possible to provide an exceedingly economical fence knob and supporting bracket therefor, that is quite rugged and will maintain its insulating ability. It is to be understood that While the drawing and accompanying description show and describe pr ferred forms of the invention, many changes may be made in the form of the invention without a change in the scope of the invention, and therefore the invention is limited only by the claims appended hereto.

What I claim is:

1. The combination of a bracket that is adapted to be secured to a fence post and a fence knob that is adapted to be secured to and supported by said bracket, said fence knob comprising a body of substantially non-conducting material that has a recess in one end thereof, said recess being provided with threads on the interior surface thereof, said bracket having a substantially plane base and a substantially cylindrical projection and a rounded section of annular form between said base and said projection, said projection having threads thereon that extend toward and merge into said rounded section of annular form, said projection having a length that is shorter than the depth of the recess in the knob, said annular section extending outwardly beyond said thread on said projection and being adapted to receive said one end of said knob and to limit movement of said knob toward the base of said bracket, said one end of the knob contacting the rounded section of the bracket when the knob and bracket are in assembled relation.

2. The combination of a bracket that is adapted to be secured to a fence post and a fence knob that is adapted to be secured to and supported by said bracket, said fence knob comprising a body of substantially non-conducting material that has a recess in one end thereof, said bracket being of resilient material and having a substantially plane base and a knob engaging p je tion and a rounded section of annular form and low height between said base and said projection, said rounded section flaring outwardly from the projection and having its smallest diameter smaller than the diameter of said recess and having its largest diameter larger than the diameter of said recess whereby said one end of said knob will engage said rounded section intermediate the upper and lower ends of said section and thus maintain a small air gap between the knob and the base of the bracket, said small air gap cooperating with the resilient material of the bracket and the configuration of the bracket to permit limited tilting of the knob relative to the base of the bracket.

3. The combination of a bracket that is adapted to be secured to a fence post and a fence knob that is adapted to be secured to and supported by said bracket, said fence knob comprising a body of substantially non-conducting material that has a recess in one end thereof, said recess being provided with threads on the interior surface thereof, said bracket having a substantially plane base and a substantially cylindrical projection and a rounded section of annular form between said base and said projection, said projection having threads thereon that merge into said rounded section of annular form, said projection having a length that is shorter than the depth of the recess in the knob, said projection and said recess being dimensioned so the knob telescopes over and encloses said projection when said knob and bracket are in assembled relation, said rounded section of annular form extending radially outwardly from the thread on the projection and having the smallest diameter thereof smaller than the diameter of said recess and having its largest diameter larger than the diameter of said recess whereby said one end of said knob will engage said rounded section intermediate the upper and lower ends of said section and thus maintain a small air gap between said knob and said base of said bracket, said air gap permitting limited tilting of the knob relative to said base of said bracket.

ALOYSIUS B. BUSSMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,013,250 Wilson Jan. 2, 1912 1,729,702 Brady Oct. 1, 1929 2,032,017 Hocher et al Feb. 25, 1936 1,065,983 Stockwell July 1, 1913 707,429 King Aug. 19, 1902 628,343 Menzel July 4, 1899 310,931 Broomhall Jan. 20, 1885 574,101 Martin Dec. 29, 1896 319,447 Broomhall June 9, 1885 303,261 Broomhall Aug. 12, 1884 1,704,472 Grandjean Mar. 5, 1929 

